Abstract

Recent evidence of vitamin D effects on non-skeletal bones, coupled with the recognition that vitamin D deficiency is common, has brought renewed attention to this hormone. Vitamin D is produced by skin exposed to ultraviolet B radiation and can also be obtained from dietary sources, including supplements. People at high risk for vitamin D deficiency include those with inadequate sun exposure, limited oral intake, or impaired intestinal absorption. Vitamin D adequacy is best determined by measuring blood concentrations of 25-hydroxyvitamin D. Average daily vitamin D intake in the general population and current dietary reference intakes are often insufficient to maintain optimal vitamin D levels. Vitamin D is composed of two bioequivalent forms. Ergocalciferol, other name for vitamin D2, can be acquired through dietary sources of vegetables as well as oral supplementation. The primary sources of vitamin D3 (cholecalciferol) were oral supplements, oily fish, fortified foods such as milk, fruit juices, margarine, yoghurt, cereals, and soy, and skin exposure to Ultraviolet B (UVB) radiation from sunlight. Apart from vitamin D-rich fish, most foods contain between 50 and 200 international units of vitamin D per serving. This value varies widely in different parts of the world because fortification can significantly increase the availability of vitamin D through the diet. Both D2 and D3 have no biological effects. After being absorbed from the intestine, they undergo liver metabolism to become 25(OH) vitamin D [25(OH)D], which is made up of 25(OH)D2 and 25(OH)D3. 25(OH)D, also known as calcidiol, is then converted by the action of the enzyme 1-hydroxylase in the kidney and other tissues to 1,25-dihydroxyvitamin D [1,25(OH)2D], also known as oestriol. The primary function of vitamin D is carried out by calcitriol, an endocrine and autocrine hormone that works by activating the vitamin D receptors in cells. Clinicians may recommend vitamin D supplementation but are unsure how to select the optimal dose and type, and how to use tests to monitor therapy. This review provides an overview of the complications of vitamin D deficiency and how to perform tests to detect vitamin D levels in the body to evaluate the performance characteristics of Fiatest Vitamin D Test Cassette.

Keywords: Vitamin D; 25-hydroxyvitamin; Fluorescent Immunoassay ; Aerobic bacteria